DESIGN AND MODELING OF ELECTRET VIBRATION SUPPRESSION AND ENERGY HARVESTING DEVICE ORIENTED TO MICRO-VIBRATION SIGNALS

With the rapid development of space technology, and the continuous improvement of the processing precision requirements of advanced manufacturing, the control and utilization of low-frequency micro-vibration signals have attracted more and more attention. Using electret materials, we developed an integrated device to solve these problems, aiming to vibration suppression and energy harvesting, for low-frequency micro-vibration environments, and established the electromechanical coupling model of the electret vibration suppression and energy harvesting device, referring to the theory of dynamic vibration absorber (DVA). In order to meet the dual requirements of vibration suppression and energy harvesting, the influence of electrostatic force on the dynamic characteristics of the system was analyzed and equivalent, the parameters of the electret vibration suppression and energy harvesting device were evaluated and an optimization method for vibration suppression and energy harvesting was presented. We established a co-simulation environment of AMEsim and Simulink, and verified the model and results by simulation. The results of modeling and simulation showed that, the electromechanical coupling model of the electret energy harvesting device established in this paper can accurately describe its motion process, and the error of modeling and simulation is less than 5%. The vibration suppression and energy harvesting device is sensitive to the changes in parameters, and electrode spacing and stiffness of the secondary structure have stronger influence on the performance than the damping. Using our proposed optimization method for different usage scenarios, the device we designed can achieve the ability of ideal dynamic vibration absorber, or obtain 1700 V output voltage and 3.1 mW energy harvesting power sacrificing 15% of vibration suppression. The electromechanical coupling model and dynamic electrostatic force analytical model established in this paper are helpful to understand the working principle of the electret vibration suppression and energy harvesting mechanism, and reveal the change process and action mechanism of the nonlinear electrostatic force.